Biomass vs oil: which carbon footprint for your new build in Luxembourg?
Compare pellet, gas and oil heating carbon impact from the early design stage. Key figures, standards and grants for architects and project owners in Luxembourg.
Who wins on CO₂: biomass or fossil?
A pellet boiler emits 30 to 50 g CO₂/kWh, versus 240-300 g for gas and around 320 g for heating oil. Biomass is treated as carbon-neutral: the CO₂ released at combustion was absorbed by the tree during its growth cycle.
Over 25 years, a single-family home using 15,000 kWh/year avoids 40 to 60 tonnes of CO₂ — the equivalent of removing 10 cars from the road for one year.
- Pellets: 30-50 g CO₂/kWh
- Gas: 240-300 g CO₂/kWh
- Oil: ~320 g CO₂/kWh
- Source: ADEME consolidated data
How to calculate the balance at design stage
Multiply the annual heat demand (per EN 16798 or SIA 380-1) by the factors below — you get the yearly balance in kg of CO₂.
ENplus pellets, sourced locally in Germany, Belgium, France or Italy, keep transport-related emissions below 5 % of the total balance.
- Pellet: 15,000 kWh × 0.04 = 600 kg CO₂/year
- Gas: 15,000 kWh × 0.27 = 4,050 kg CO₂/year
- Oil: 15,000 kWh × 0.32 = 4,800 kg CO₂/year
- ENplus pellets = transport < 5 % of balance
What regulation requires for your building permit
Since 2022, every new biomass boiler must meet EcoDesign 2022 and EN 303-5 Class 5 to qualify for Klimabonus. These standards cap dust emissions under 60 mg/Nm³ and require a minimum efficiency of 87 %.
Include the standard references in your permit file — it speeds up review and avoids back-and-forth with the building authority.
- EU Regulation 2015/1189 = biomass EcoDesign
- EN 303-5 Class 5 = efficiency + emissions
- Only wood pellets trigger the state grant
- ENplus = consistent fuel quality
Maximise subsidies without oversizing the system
Klimabonus 2026 pays up to €8,000 for a pellet boiler in a single-family home replacing an old system. Without replacement, the grant still stands at €4,000. Add +15 % with a buffer tank and €1,000 flat with thermal solar.
Municipal aid varies sharply: some communes almost double the state amount, others grant nothing. The Klima-Agence simulator shows your real envelope in under one minute.
- Single-family: up to €8,000 (€4,000 without replacement)
- Multi-unit: €6,000/dwelling, capped €40,000
- District heating: €6,000, capped €24,000
- Buffer tank: +15 % | Solar: +1,000
Sources
Need personalised advice?
Our team supports you with selection, sizing and subsidy paperwork.